Monday, January 15, 2018

This Week and The End of Empire

1. Database truth of the week

"ALL
names are human created, either by non-algorithmic assignment, or via
some algorithm. We ONLY know that two types of objects are distinct
because they have different sets of defining properties and, for a given
object type, we ONLY know that two objects are distinct because the
values (observed or measured) of that object type's defining properties
are distinct. Names (of objects of some type) allow us to distinguish
two such entities ONLY when they are 1:1 with the values of the object
defining properties. Two sets of names (whether human assigned or
machine generated) consistently identify the same set of entities ONLY
when they are 1:1." --David McGoveran

2. What's wrong with this database picture?

"I have to maintain some lists in DB (SQLServer, Oracle, DB2, Derby), I have 2 options to design underlying simple table:"1st:

NAME VALUE================= dept HR dept fin role engineer role designer-----------------

UNIQUE CONSTRAINT (NAME, VALUE) and some other columns like auto generated ID, etc.

UNIQUE CONSTRAINT (NAME) and some other columns like auto generated ID, etc.

"There
is no DELETE operation, only SELECT and INSERT/UPDATE. In first
advantage is only INSERT is required but SELECT (fetch all values for a
given NAME) will be slow. In second SELECT will be fast but UPDATE will
be slow. By considering there could be 10000s of such lists with 1000s
for possible values in the system with frequent SELECTs and less
INSERTs, which TABLE design will be good in terms of
select/insert/update performance." --SQL TABLE to store lists of strings, StackOverflow.com

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3. To Laugh or Cry?

Q: "Is the WWW a relational database?"

A:
"No, if you’re searching for a database metaphor for the World Wide
Web, the closest would be a highly-distributed Network model database,
with strong elements of Document-oriented databases. You don’t “query”
the WWW - you traverse nodes as you would a network or Graph database,
although search engines like Google provide some element of archival
querying of the WWW. Like all network-model databases, “joins” on the
world wide web are physical links (or at least indirect physical links)
using URLs. The fundamental thing that distinguishes these types of data
joins from relational database joins is that relational joins are
always computed from the data."

A:
"This is an interesting question. As others have said, the short answer
is no. What is WWW then? And does it in any way relate to relation
databases? WWW is the prefix you see on many URLs. (i.e. www.quora.com).
It is used by your browser to figure out where to send requests for web
based information. Behind the scenes, a service called DNS is used to
convert the URL into an IP address which your browser then uses to
communicate with the web server. Many of the web sites that have a URL
that starts with WWW utilize relational databases to store and manage
the information that is presented by the web site. But many other WWW
web sites use non-relational databases (like mongo) or no database at
all (i.e. static web sites)." --Is the WWW a relational database, quora.com

4. I Told You So

"Those
who are in love with practice without theoretical knowledge are like
the sailor who goes onto a ship without rudder or compass and who never
can be certain where he is going. Practice must always be founded on
sound theory." --Leonardo DaVinci

6. Housekeeping:

To work around Blogger limitations, the labels are mostly
abbreviations or acronyms of the terms listed on the FUNDAMENTALS page. For
detailed instructions on how to understand and use the labels in conjunction
with the FUNDAMENTALS
page, see the ABOUT
page. The 2017 and 2016 posts, including earlier posts rewritten in 2017 are
relabeled. As other older posts are rewritten, they will also be relabeled, but
in the meantime, use Blogger search for them.

The life histories of great states are amazingly similar, and are due to internal factors. Their falls are diverse, because they are largely the result of external causes." --Sir John Glubb, THE FATE OF EMPIRES AND SEARCH FOR SURVIVAL (William Blackwood and Sons, 1978)